The present invention relates to the field of winding stator cores, such as those employed in electric motors, using winding shuttles having a reciprocatory and oscillatory motion. In particular, the present invention relates to methods and apparatus for a winding station stator core positioning system whereby stator cores of different lengths may be wound by a winding shuttle without replacing the winding needles or other time-consuming adjustments.
Modern stator winding equipment typically includes a pair of outwardly opposed needles disposed at one end of a shuttle, through which needles coil wire is laid in turns upon the poles of a stator core. The stator core is positioned with its longitudinal axis aligned with that of the winding shuttle output shaft. The shuttle is capable of reciprocatory motion along the longitudinal axis of the stator core, whereby the needles traverse a path parallel to the longitudinal axis of the stator core, in a manner per se known. Such a winding machine is described in Luciani et al. U.S. Pat. No. 4,858,835.
In presently existing machines, the stator core is positioned adjacent to the winding station with its proximal edge (i.e., that nearest the winding station) at a fixed distance, which fixed distance is independent of the stator length. When it is desired to wind a stator core of a different length, it is necessary to adjust the longitudinal stroke of the winding shuttle. Adjusting the stroke length in presently existing machines requires the operator either to change the winding needles for those of a suitable length or manually to adjust the needles to proper length, where the needles include a mechanism for varying their length. The needle replacement task requires removing the needles from the shuttle, selecting needles of the appropriate length for the stator core to be wound, rethreading the coil wire through the newly installed needles and verifying that the correct coil wire tensioning has been achieved. Such needle replacement or adjustment operations are both time consuming and require manual operator intervention, thereby reducing the overall productivity of the winding station.
Lead termination equipment located at the stator winding station, such as that described in commonly assigned copending U.S. application Ser. No. 07/321,919, filed Mar. 13, 1989, may be used to anchor the lead wires extending from the stator coils to the stator terminal board or pallet. In presently known winding station configurations, this equipment is typically located at a fixed distance from the proximal face of the stator core. While it is not generally necessary to reposition this equipment when winding stator cores of different lengths, such capability may be desirable when changing lead anchoring conditions or when a different type of stator terminal board is used.
In view of the foregoing, it is an object of the present invention to provide methods and apparatus for automatically adapting a stator winding station to wind stators of different lengths with a minimum of operator intervention.
It is a further object of this invention to provide methods and apparatus for automatically adapting a stator winding station for winding stator cores of different lengths without changing or adjusting the needles installed in the winder.
It is a further object of this invention to provide methods and apparatus for improving the overall productivity and cost-effectiveness of a stator core winding station by minimizing the down time associated with adjusting the winder for stator cores of different lengths.
It is yet another object of this invention to provide methods and apparatus for automatically repositioning lead termination equipment, used with a stator core winding station capable of automatic set-up, for different length stator cores.